For 4WD vehicles, the rear leaf springs may be deformed around the centre due to an imperfect manufacturing method, and high localized stress may occur around the deformed area, which may cause the paint to peel. If this occurs, the rear leaf springs may corrode due to exposure to snow melting agent etc. and crack around the deformed area. Such cracks may grow if neglected, and in the worst case, the springs could break, which could cause the vehicle to stall.